%0 Journal Article
%T Novel Ag/Kaolin Nanocomposite as Adsorbent for Removal of Acid Cyanine 5R from Aqueous Solution
%A Saeedeh Hashemian
%A Mohammad Reza Shahedi
%J Journal of Chemistry
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/285671
%X Ag/kaolin nanocomposite was prepared by reduction of Ag+ ion with ethanol at alkaline condition on kaolin surface. Nanocomposite was characterized by FTIR, XRD, TEM, and BET methods. Results showed the Ag/kaolin composite has particle size 50£¿nm. The surface area was increased from kaolin to Ag/kaolin from 1.0215 to 7.409£¿m2£¿g£¿1, respectively. Ag/kaolin nanocomposite was used for adsorption of acid cyanine 5R (AC5R) from aqueous solution. The effect of parameters such as contact time, pH, and mass of nano composite has been investigated. The maximum percentage of adsorption of AC5R was found at pH 3 and contact time of 60£¿min. The higher percentage removal of AC5R by Ag/kaolin than kaolin can be attributed to catalytic activity of Ag on the surface of kaolin. The experimental data was fitted by pseudo-second-order kinetic model. The adsorption isotherm data could be well interpreted by Langmuir isotherm model. From the results of thermodynamic study, the adsorption process of AC5R onto Ag/kaolin nanocomposite was spontaneous and endothermic process. The process is clean and safe for purifying of water pollution. 1. Introduction The effluent from many chemical and textile industries is major source of water pollution. They contain organic compounds and dyes. Many colors and dyes are toxic and carcinogenic. Large volumes of colored aqueous effluents are discharged to environment by the various divisions, such as textiles and painting. Numbers of techniques are available for the treatment of wastewater such as photocatalytic degradation, coagulation, electrochemical technique, and adsorption [1¨C7]. Adsorption has proven usual process, more efficient, and economically feasible for the removal of variety of contaminants [8¨C12]. Adsorption of some dyes and organic compounds with different sorbents was investigated [13¨C15]. Adsorption of cyanine dyes to solid surfaces has evoked interest from both a basic and technological point of view. The adsorption behavior of some cyanine dyes has been studied [16]. Adsorption on the surface of semiconductor powders such as ZnO, TiO2, AgCl and on silica, are some of the interesting applications of the dyes adsorbed on a solid surface [17]. Mineral clays are widely applied in ceramics, paper filling and coating, catalysts, adsorbents, and nanocomposites [18¨C24]. Mineral clays have been extensively studied for potential applications as environmental remediation agents to remove heavy metals and organic contaminants from water. The montmorillonite and kaolin group clays were used as adsorbent [25, 26]. Kaolin is one of the
%U http://www.hindawi.com/journals/jchem/2013/285671/